Protective Effect of Betula Platyphylla on Ultraviolet B-irradiated HaCaT Keratinocytes

Abstract

Objectives: Betula Platyphylla(BP) has been used as a analgesic, anti-microbial, anti-oxidant drug in Eastern Asia. However, it is still unknown whether BP ethanol extract could exhibit the inhibitory activities against ultraviolet B(UVB)-induced skin injury on human keratinocytes, HaCaT cells. This study was aimed to investigate the protective activity of BP ethanol extract on UVB-irradiated skin injury in HaCaT cells.Methods: The skin injury model of HaCaT cells was established under UVB stimulation. HaCaT keratinocyte cells were pre-treated with BP ethanol extract for 1 h, and then stimulated with UVB. Then, the cells were harvested to measure the cell viability, production of reactive oxygen species(ROS), pro-inflammatory cytokines such as interleukin(IL) 1-beta, IL-6, and tumor necrosis factor(TNF)-<i>α</i>, hyaluronidase, type 1 collagen, matrix metalloproteinase(MMP)s. In addition, we examined the mitogen activated protein kinases(MAPKs) and inhibitory kappa B alpha(I<i>κ</i>-B<i>α</i>) as inhibitory mechanisms of BP ethanol extract.Results: The treatment of BP ethanol extract inhibited the UVBinduced cell death and ROS production in HaCaT cells. BP ethanol extract treatment inhibited the UVB-induced increase of IL-1beta, IL-6, and TNF-<i>α</i>. BP ethanol extract treatment inhibited the increase of hyaluronidase, MMP and decrease of collagen. BP ethanol extract treatment inhibited the activation of MAPKs and the degradation of I<i>κ</i>-B<i>α</i>.Conclusions: Our result suggest that treatment of BP ethanol extract could inhibit the UVB-induced skin injury via deactivation of MAPKs and nuclear factor kappa B(NF-κB) in HaCaT cells. This study could suggest that BP ethanol extract could be a beneficial agent to prevent skin damage or inflammation.